Method of and apparatus for controlling a characteristic of a material



De'.-25, 1934. T. A. BRYSON I I METHOD OF AND APPARATUS FOR CONTROLLING A CHARACTERISTIC OF A MATERIAL Filed Oct; 23, 1931 2 Sheets-Sheet 1 \/NVEN Ta R 750a? A. 5/95 0/? WW ATTORNEYS- 25,1 934. QT. A. BRYSON 1,935,312 I METHOD OF AND APPARATUS FOR CONTROLLING A CHARACTERISTIC OF A MATERIAL Filed Oct. 23 1951 2 Sheets-Sheet 2 /Nl/EN7'0R Emmy/4. Ergson .r .ATTQRNEYS Patented Dec. 25, 1934 VMETHOD 0F 1,985,312 v AND APPARATUS FOR con- TROLLING A CHARACTERISTIC OF A MA- TERIAL Tandy A, Bryson, Troy, N. Y.

Application October 23, I 18 Claims.

My invention relates to a method and apparatus for controlling such characteristics'of a fluent or plastic material as its' consistency, turbidity, acidity, alkalinity, viscosity, plasticity, density, color, or in fact any characteristic the variations in which are readily measurable either directly as such or, indirectly by their effect on a characteristic which is readily measurable; For

example, the regulation and'control of the con-' .sistency of a mixture may involve, as one step, a direct measure of the consistency because this can readily be done. 0n the other hand, the regulation' and control of the acidity of a mixture mayinvolve as one step, the indirect determination of the acidity by measuring'the viscosity, color or any other characteristic which is aiTected by or varies with the acidity.

Broadly, my invention contemplates first, .the use of any appropriate means for continually measuring or determining the particular characteristic to be controlled, the variations in which i will be utilized to effect variations, from a predetermined standard, in the speed of a moving element. Second, it contemplates the use of appropriate means for quickly detecting variations in speed of the moving element as effected by variations in the characteristic to be controlled, and the direct utilization of this speed-variationdetecting-means for controlling additions to or withdrawals from the material; I p

In its preferred embodiment, the means contemplated by my invention for controlling a characteristic of a material includes only three moving elements; one of which moves at a rate of speed which is dependent upon the characteristic to be controlled 'and'varies' therewith; one of which moves at a substantially constant predetermined speed and which said speed is or may be the same speed at which the first element moves when the characteristic conforms to a prescribed standard; and one of which moves re-. -sponsive to differences in speed of the first two elements mentioned andmay be used to efiect a direct control of the characteristic. venience, the movement of each of these elements is preferably one of rotation.

One of the objects of my invention is to provide a means and method for controlling a characteristic of a fluent orplastic material which will be extremely sensitive in its operation whereby a fairly uniform'rather than average regulatior'i'is attained. Another object isv to provide a device of the character described in which variations of the characteristic to be controlled will be immediately reflected in the operationof For con- 1931, Serial No. 570,725-

means ior applying a corrective, and in which the degree or extent of application of the corrective will be directly proportional to the degree or extent of the variation'of the characteristic from a prescribed standard. Another object is to pro'-- vide a novel means extremely sensitive to variations in the controlled characteristic for directly applying a corrective thereto. A further object isto provide a characteristic controlling means which may be used in combination with substantially any means employed or adapted for measuring or determining the characteristic to be, controlled. j

With. these and other objects in view which will be apparent from a reading of the speciflca- 5 tion, my invention includes the novel elements and the combination and arrangements thereof described below and illustrated in the accompanying drawings showing the application thereof in the paper making art to controlling the consist- 'ency of-paper stock. It is, of course, understood that my invention is in no sense limited thereto.

Fig.1 is a plan view of a device embodying one form of my invention;

Fig. 2 is a side view illustrating diagram,- matically a modified form of certain elements of my invention;

Fig. 3 is a detail view of a. differential mecha nism actuated by the respective floats in Fig. 2 for varying an electric current in accordance with variations in the consistency of the material;

Fig. 4 illustrates. a modified form of rheostat operated by the floats in Fig. 2;

Fig. 5 is a diagram of connections for Fig. 1;

Fig. 6 is a diagram of connections for the arrangement illustrated in Figs/2, 3, 4 and "(,and

Fig. 7 is a fragmentary plan' view of a modified form of my invention.

Like reference characters indicate like. parts throughout the drawings.

One embodiment of my invention in which variations 'in the characteristic to be controlled 1 are reflected in the speed variations ofa pump rotor or other element moving in the material is illustrated in Fig.- 1. Here, 10 is the pumpwhich, for the purpose of exemplifyingmy invention, may be assumed to be any pump regularly employed 1 in a paper mill for forcing paper stock from a supply pipe 11 to a discharge pipe 12. The pump is driven by a substantially constant impelling force, here'shown as a motor 13 through shaft 14 and a flexible coupling 15. I

The control mechanism of my invention which is common to all embodiments includes a ditv 32. A motor 33 is operated at a substantiallyconis constant, the pump motor will operate at 9. 0f the materialferential gearing indicated generally at 16 and tion characteristics so that any change in power mounted on a shaft 1'! having its bearings at 18 line conditions will exercise the same effect on in standards 19. Twobevel gear wheels 20 and both motors. By arranging the motors in this 20a 'arerotatably mounted on the shaft and to manner, no reasonable variation of power supply these wheels are secured sheaves 21 and 21a reconditions will afiect the consistency.

spectively. A second set of gears 22 and 22a are Hunting or oversensitivity may be avoided by rotatably mounted on studs 23 in a differential a sufliciently great speed reduction between the ,carrier 24 and mesh with the gears 20 and'20a, motors and the gear set. The greater the speed respectively. The studs 23 are secured to the carreduction, the l n r h interval of time between rler 24 which is, in turn, secured to the shaft 17. an indicated variation in consistency and its cor- The gears 22 and 22a are held in position by collars rection. The need forthis character of adapta- 25 secured on the studs 23, and the gearing is held tion arises particula y in cases W e th measin proper mesh by collars 26 and 26a secured to urement of the consistency may, in different P- the shaft 17. The shaft 17 drives "a, t 27 pllcations of the device, take place at various disthrough coupling 23, d thi t t t a tances from the point where dilution takes place, valve 29 controlling the admission of a diluent, 0r fi t of i ut s slower in p du in such as water, from apipe 30 to the supply pipe 11. thedesireq results, vice ve sa- The shaft of the motor 13 is extended on the In th alapp at 0f the d v a Side remote from the pump and carries a pulley manually operated clutch coupling 99 between the 31 which is connected to the pu11ey 21 by b lt shaft 17 and the valve stem 27 is desirable in order that the valve opening may be set by hand stant predetermined speed, and is connected to and h Speed Of h w m rs adjusted for the the pulley 21a by a belt 34, Th meter 33 is prodesired consistency. When the parts are thus advided with a, speed regulating d i i h i justed, the shaft will be clutched to the valve stem, manually operated to adju t th d, so t t whereafter the regulator will maintain the deconforms to the speed of motor 13 when pump 10 sired Consistency-l is handling stock of the desired consistency. In the embodiment of my invention llust a ed In operation, assuming that the consistency of in Figs- 2 end a heater is represented generally the material varies, then, since the difierence in at The Slope O thesurfaee 0f e S ufl in a fe d gnddischarge h ad t d from t pump gravity type beater depends upon the consistency Two floats 36 and 37, spaced speed d t r i d by th power necessary t qalong the material in itsdirection of flow, by their some th difference in head when handling a difierence in level, measure the consistency of the terial of a given consistency. The motor 33 havstllfi- Flexible members 38 and 39, Such as chains 111g been t t run t a substantially fixed speed or ropes, are attached to the floats 36 and 37 rehl h is th same as t normal speed of the spectively and pass over sheaves 40 and 41 to counmotor 13 when the fluent material is at the desired terweights 42 and respectil'lyi the cable 33 consistency, then, under normal conditions, also passing over an idler401. "I'he relative posimotors 13 and 33 are operating at the same speed of the Sheaves 40 41 1s measure of h b t i opposite directions, andrthe sheaves 21 and consistency of the material; The difierence 1n 21 and hence t gears 20 and 20 are rotating level betweenthe two floats, rather than the abat th same peed a in opposite directions, with solute levels is, therefore, the determining factor.

will be above or below as the case may be.

tive to the speed of the control motor 33. That is to say, if the consistency of the stock changes, this will be immediately reflected by a corresponding change in the speed of motor 13 which the speed of motor 33, Y

When motor 13 is running at greater speed than motor '33 the differential carrier 24 will be turned in one direction, and when lt runs atlesser speed than motor 33 the carrier will be turned in the opposite direction. Since the carrier 24 is secured.

to the valve stem 27 this element will be turned to eflect a corresponding closing or opening move-' ment of the valve and thus increase or decrease the volume of diluent admitted to pipe 11. It will of course be understood that the sensitivity oi the device may be governed by the selection ofa pump motor having a suitable torquei-speed characteristic and that the speed of the control motor 33 may be set by any or the common speed control means. As a practical matter, it maybe desirable to select for the control motor In Fig. 3, I have illustrated a means by which v the relative positions of the two sheaves, and therefore the measure of consistency of the stuff, may be caused to vary an-electric current and thereby bring about the desired regulation of the The lnteriorly threaded hubs 44 of the sheaves 40 and 41 engage threads on a shaft ,"45 suppbrted in brackets 46. A resistor 47, which may comprise a. plurality of carbon discs is mounted on shaft 45 between the sheaves 4'0 and 41. As the sheaves turn on the threaded portign of the shaft 45, they move to the right or to the left as the case may be. The pressure on this rheostat is obviously due to'the difference in movement of the two sheaves. It they both move'the same amount in the. same direction, there will be no variation in pressure on the resistance. Any change in volume of the stud in the beater will cause both floats tomove vertically t o the sam e extent and tion in the consistency of the material, will move one having a torque curve similar in shape to riable rheostat47' in which electrodes 49 and 50 that oftbe pump motor, and to drive both motors are submerged in a fluent conducting materialSl,

from the same source of electric power; in other and their. distance apart varies the current-man words, to have for the two motors regula} electric circuit in accordance variations in equipped with a pointer and a dial calibrated and 50 are connected by flexible members 381 and 391 to floats as shown in Fig. 2, the distance apart of the electrodes correspondingto the difference in level of the floats and thereby affording a measure of the consistency of the material. The

' electrodes 49 and 50 are connected to an electric circuit by conductors 52.

Fig. illustrates a diagram of connections for the embodiment of my invention shown in Fig. 1. In this type the variations in the speed of motor 13 which drives the pump are efiected directly by variations in the consistency of the material being handled by the pump. The speed of motor 33 is adjusted by means of the rheostat' 48' to conform to the normal speed of motor 13 when the stock is at the desired consistency, and hence the differential mechanism controlling the diluent valve is held stationary at normal consistency. Any-variation in consistency, is immediately reilected in a speed diilerential between motors 13 and 33 which eifects an opening or closing of the diluent valve and a correction of the consistency. I have illustrated .in Fig. 6 a diagram of connections forthe arrangements illustrated in Figs. 2, 3 and 4 taken in connection with that shown in Fig. '7. In this case the motor 131 merely drives one side of the differential and is not connected to the pump. The speed'of the motor 131 varies in accordance with the resistance of the rheostat '47 which in turn varies in accordance with the consistency of the material, as pointed out above.

'- The motor 331 may be adjusted, by means of rheostat v48, to rotate at adesired predetermined speed conforming to the speed of motor 131 when the material is at standard consistency. The motors 131 and 331 operate difierential 16 and thereby controlthe characteristic of the fluent material-as above described.

. While in the embodiment of my invention illustrated, I have shown a device for measuring and controlling the consistency of a fluent material such as paper pulp, it is to be understood that my invention is also applicable tothe measurement and control of a "characteristic other than consistency. For example, the characteristic that is to be measured and controlled may be density,

- turbidity, alkalinity, acidity, translucency or the like. Turbidity or -'color' may be measuredand controlled by a photo-electric cell, while density or viscosity-may be measuredand controlled by flowv through an orifice, by difierential floats, or by the resistance of 'a-rotor whirled in the material. Furthermore, one characteristic may be used as a guide for the correction of another. For example, acidity may be difiicult to measure,

but it may cause a'change in viscosity whichis easy to measure. In that case the viscosity of 4 the material would be measured and means provided for controlling the addition of the necessary amount of a neutralizing agent, The measured characteristic, therefore, is not necessarily the controlled characteristic of the material.

- From the foregoing, many marked advantages of my invention are apparent. Among these may be noted the extremely simple ijiethod anrhmeans -for setting the mechanism to maintain a desired consistency. All that is necessaryis to regulate the speed of l the control motor by means 01 a suitable rheostat which. may, if desired,- be

. in consistencies. Operating at normal consistency quired to transmit is only that necessary to operate the valve. I-lence,this element may be made very small and light. Another novel feature of considerable advantage resides in the utilization, as a characteristic measuring device, of a piece of equipment normally employed in the manipulation of the material. In the embodiment shown in Fig. 1 the pump 10, for example, may be any pump normally used in the processing for raising the material against a constant difierence in head. No auxiliary equipment for measuring the consistency is necessary; and furthermore the consistency is determined from the whole mass of material rather than from a by-passed sample.

While I have described my invention in its preferred embodiment, it is to be understood that the words whichI have used are words of description rather than of limitation and that the drawings are merely illustrative. Hence, changes within the purview of the appended claims may be made without departing from the true scope and spirit of my invention.

vWhat I claim is:

1. The method of controlling a characteristic of a material of variable character which comprises moving an element at a speed varying in accordance with variations in the character of said material as effected by variations in. said characteristics, moving a second element at a substantially constant predetermined speed and controlling the said characteristic of said material in accordance with variations in the relativespeeds of said elements. 1

2. The method of controlling the consistency of fluent or plastic material having a variable character which comprises rotating an element at a speed varying in accordance with variations in the character of said material as efiected by the consistency. thereof, rotating a second 'element at substantially constant speed and controlling the consistency of said material in accordance with variations in the relative speeds of rotation of said elements.

3. The method of controlling the consistency of fluent or plastic material having a variable character which comprises moving an element in said material at a speed varying in accordance with variations in the consistency thereof, moving a second element at a substantially constant speed, and controlling the consistency of said material in accordance with variations in the relative speeds of said elements.

v 4. The method of controlling the consistency of fluent or plasticmaterial having a variable of rotation of'said elements.

5. In a' device for controlling a characteristic of a material of variable character, a first element, means for moving' said element at a speed varying in accordance with variatigns in. t

character of said material as eiiected by variations in said characteristic, a second element,

means for moving said second element at a substantially constant predetermined speed, and means responsive -to the relative speed'of said elements for controlling the said characteristic.

6. In adevice' for controlling acharacteristic or; fluentmaterial, a." first-rotatable element,

means forrotating said element at a speed -vary-' ing-in accordance with variations in the characsaid characteristic, a second rotatable element,

means for rotating said second element at a substantially constant predetermined speed, and

means responsive to the relative speeds of said elements for correcting the said characteristicof said material.

7. In a device for controlling the consistency of fluent material, a difierential gear, means responsive to variations inthe consistency of said material for rotating a first element of said gear, means for rotating a second element of said gear at a substantially constant speed, means for admitting a diluent to said material, and means responsive to variations in the relative speeds of the two elements of said gear for controlling the amount of diluent admitted to said material.

8. In a device for controlling a characteristic of a material of variable character, the combination with a differential mechanism including two driven elements and an element rotatably responsive to difierences in speed of the driven elements, of means for driving one of said driven elements at substantially constant predetermined speed, means for driving the other of said elements at a speed varying with variations in the characteristic to be controlled, and means operable by the element responsive to difierences of the rate of movement of said second element to conform to the rate of movement of said first element when said characteristic conforms to a prescribed standard and means responsive to the .relative speed'of said elements for controlling said characteristic.

10. In a device for controllinga characteristic,. of a material of variable character, a first element, means for rotating said element at a speed varying in accordance with variations in the character of said material as eifected by variations in said characteristicya second element, means for rotating said second element, means for adjusting the rate of rotation of said second element to conform to the rate of rotation of said first element when said characteristic conforms to a prescribed standard, and means responsive to the relative speed of said elements for controlling said characteristic. 1

11. In a device for controlling the consistency of fiuent material, a pipe through which the said material flows, a pump for'forcing the material therethrou'gh, a differential gear, a motor operating said pumpand actuating a first element ofsaid gear, means for actuating a second'element of said gear at a substantially constant speed, and a means' responsive to variations in the relative speeds of'the two said elements of said diflerential gear for controlling the consistency of said material. l 1

12. In a device for maintaining paper stock at v 1,985,312 ter of said material as effected by variations in a-l predetermined consistency, the combination with a stock pump, of a difierential gear, a motor for driving said pump and one side of said gear at variable speeds depending upon the consistency of the stock, a second motor for driving the other side of said gear at a substantially constant predetermined speed, and means operated by said gear for controlling the quantity of water in the stock.

13. In a device for controlling the consistency of fluent material, a differential gear, a pipe through which the material flows, a pump interposed in said pipe for pumping the material, a motor operating said pump and actuating a first element of said differential gear, means for actuating a second element of said gear at a substantially constant speed, means for admitting a diluent to said material, and means operable in accordance with variations in the relative speeds of the two said elements of said gear for controlling the admission of the diluent.

14. In a device for controlling a characteristic I of a material of variable character, the combination with means for determining variations in said characteristic, of a movable element, means for moving said element, means responsive to variations in, said characteristic for varying the rate" of movement of said element, and means controlled by, variations in the rate of movement of said element for controlling said characteristic.

15. In a device for controlling a characteristic of a material of variable character, the combination with a movable element, of means for mov ing said element, said means being responsive to variations in said characteristic for controlling the rate of movement of said element, and means actuated by said first mentioned means when its rate of movement difiers from a predetermined standard for controlling said characteristic.

' 1 6. In a device for controlling the consistency of fluent material, a first movable element, means for varying the rate of movement of said ele- -ment in accordance with variations in the consistency of said material, a second element rotatable at a substantlally constant speed, and means responsive to the relative speeds of said elements for controlling the consistency of said material.

1'7. In a device for controlling a characteristic of a'fiuent or plastic material a variation in which characteristic effects a variation in the fluency or plasticity of said material; the combination with relative speeds of said motors for controlling the consistency of the stock.

TANDY A. BRYSON.

second motor to a desired, substantially constant rate, and means responsive to variations in the 

